1. Field of the Invention
This invention is directed to a tamper evident cap assembly that is connectable to a fluid loaded syringe in protective, sealing relation to a nozzle and discharge port of a syringe. A body includes a flow restricting member that in the preferred embodiments is interconnected with and defines a one piece construction of the cap assembly. The flow restricting member is structured to facilitate a snap-fit connection of the cap assembly on the syringe, thereby sealing the discharge port thereof. Tampering is indicated by a separation of the flow restricting member and the body, by detachment of the body from the syringe when a predetermined force, sufficient to remove the body from the syringe, is exerted on the body.
2. Description of the Related Art
In hospitals or other medical care facilities, it is very common for medical doctors and other authorized medical personnel to order that a patient be given a drug or medication by injection. In fact, it is currently estimated that more than 16 billion injections are administered on a worldwide basis in any given year.
As a result, it is becoming relatively common in hospital settings for a number of syringes to be pre-loaded or filled by a pharmacist, or other authorized personnel within a hospital or similar facility, at an appropriate location for subsequent dispensing of same to one or more patients. The pharmacy or other location where syringes are filled can and often will be located in a remote part of the hospital, relative to the patient care area where the injection is to be administered. In some cases, the loading of syringes occurs in another building or facility entirely, often referred to as “third party pharmacies.” This may even be a growing trend among hospitals to limit certain costs. Regardless, a syringe filling station at a large medical facility may resemble a factory, from which drug loaded syringes are delivered to a large number of nurse's stations in multiple hospital or medical buildings. Because many nurse's stations are typically located very remote and from a syringe filling station, a loaded syringe is quite often given to another person for delivery to a nurse's station, for subsequent dosing of the patient by qualified personnel. From the foregoing, it may be understood that during the course of loading a syringe with a drug, and also afterwards, when a loaded syringe is delivered to a nurse's station, or even subsequently to a patient, the syringe can easily be handled by more than just one or two people.
Also, and especially in the case of a very expensive drug or an addictive drug, such as but not limited to morphine, there is some danger that a pre-loaded syringe will be tampered with by a person seeking to improperly gain access to the drug, whether to use it himself, or to try to sell it illegally. A resulting danger also exists in that if an unauthorized person were actually to access to the prescribed medicine, he or she might inappropriately substitute saline solution or some other unauthorized substance in the syringe in an effort to avoid detection. By way of example only, if saline solution were substituted for a dose of morphine, this could have extremely serious consequences. Thus, the growing use of syringes which are pre-loaded with a drug presents another problem in that it is important to know if the sealed and/or pre-loaded syringe has, or has not, been tampered with and exposed to contamination or might otherwise have been compromised.
The benefits of using a pre-filled syringe, and of being able to readily determine whether or not it has been tampered with, are abundantly clear. Drugs and medications are specific to each particular patient's disorder or disease being treated. In addition, interactions between drugs and medications given to a patient incorrectly can have serious and deadly consequences. It is, therefore, important to know that a particular medication being injected is, in fact, the drug that was prescribed by the treating physician, and that it has not been replaced by another compound. Moreover, some drugs can have harmful effects in large doses. Accordingly, it is also important to ensure that the proper dosage is followed, as prescribed. Since pre-filled syringes are prepared in advance of being delivered and used, they may be loaded carefully by a pharmacist or other similarly qualified individual to ensure the appropriate medication and dose is prepared. This reduces errors on injection by nurses or physicians who may be in a stressful or time-sensitive situation and may not have the luxury of verifying the correct medication or measuring out a dose, particularly small doses, from a source vial.
Pre-filled syringes are also particularly useful in view of the recent shortage of medications and other injectables, such as narcotics or epinephrine for example. Some drugs and medications, even those which are essential for treating life-threatening diseases, are currently in drastically short supply, due to several factors. For example, during the manufacturing process of some medications, it can occur and has happened for whole batches to become contaminated, such as by bacteria or other microorganisms that could cause infection upon injection, thereby rendering quantities of medications unusable, which in turn, reduces the overall stock of available medications. In addition, manufacturing capacity issues, such the availability and increased cost of raw materials and transportation, as well as lower profit margins, are contributing factors that also result in reduced quantities of medications being produced, and therefore, available to patients. Accordingly, the supply of drugs that are available and safe for use is a starting to be viewed as a precious commodity, with little to no room for waste. The use of pre-filled syringes helps significantly to ensure that only the exact amount of medicine or drugs prescribed are being used, thereby helping to eliminate waste. Also, by having a pharmacist or other qualified person at a filling station preparing the pre-filled syringes, even at a location distant from the patient treatment site helps to ensure that the exact amount of medication needed is delivered. This also circumvents the theft of drugs by “accidental” taking of excess medication, such as to siphon some off for personal use or another non-prescribed purpose, which has unfortunately been known to occur. Accordingly, the use of pre-filled syringes helps maintain the stock of these important drugs so that they may be available to the patients truly in need of them. Further, any unused pre-filled syringes may be recycled so that unused medication does not go to waste. This is only possible, however, if there is some way to determine that a pre-filled syringe has not been tampered with or compromised, thereby verifying the integrity of the contents.
There is has historically been a problem, however, of knowing if a sealed, preloaded syringe has, or has not, been compromised by it being tampered with or might otherwise have a loss of sterility or become contaminated. This and related types of problems have been described in the inventor's own previously granted U.S. Pat. No. 4,667,837 and in other patents, such as U.S. Pat. No. 5,328,474. Despite attempts in the past to prevent unauthorized access to syringe(s) pre-loaded with a drug or medication, it is understood that some problems continue to exist in this field of art and there remains an ongoing need for further improvements, despite the introduction of inventive products according to the above-noted two patents and others.
For instance, there remain problems of manufacturing such products in a manner which is relatively easy and inexpensive, as well as some problems involved with the assembly and placement onto a drug loaded syringe, such as at a drug filling station. Other problems exist relative to maintaining the sterility during storage at the manufacturing facility of the end caps, and during transport of them to a hospital or other medical facility, during storage of them at a hospital or other medical facility, including any transport to a nursing station and ultimately, to a patient care area.
Accordingly, there is a need in this area for an improved tamper evident cap assembly, which is capable of being used with standard or conventional pre-loaded syringes in a manner which overcomes problems and or disadvantages of the type set forth above. If any such improved end cap assembly were developed, it would preferably have certain structural and operative features such as, but not limited to, being at least initially of a one piece construction in order to facilitate appropriate connection to a preloaded syringe. In addition, if any such improved end cap assembly were developed, it would preferably also be structured to provide a clear and unmistakable indication of tampering or of previous access to the contents of the preloaded syringe. Finally, if any such improved, tamper evident end cap assembly were developed, it would ideally also be structurally and operatively reliable, while still remaining relative easy and cost effective to make and assemble, in order to facilitate widespread use and acceptance through out the medical profession. From the foregoing, one might appreciate that the present invention seeks to address such problems, and others, associated with the handling of end caps including, but not limited to, tamper evident caps and luer lock caps during their manufacture, and also during the assembly of them and/or use at different stations and/or by different persons.